Horn for sound instruments



March 11 1924. 1,486,650

L. FOLEY HORN FOR SOUND INSTRUMENTS Filed March 5, 1923 i EZ-Z Patented Mar. 11, 1924.

UNITED STATES PATENT OFFICE.

ARTHUR L. FOLEY, 0F BLOOMINGTON, INDIANA, ASSIGNOR TO GEORGE FABYAN, OI

BIVEBJBANK, ILLI'N0IS.

HORN For. sourm INSTRUMENTS.

Application filed Mai-c118, 1923. Serial No. 622,472.

To all whom it may concern:

Be it known that I, An'rnun L. FOLEY, a citizen of the United States, and a resident of Bloomington, in the county of Monroe and State of Indiana, have invented certain new and useful Improvements in a Horn for Sound Instruments; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings and to the numerals'of reference marked thereon, which form a partof this specification.

In many instruments dealing with sound, a horn is usedas a sound amplifier, either to increase the total intensity. or the'ins tensity in a 'ven direction,.of.the sound produced by t e instrument itself, or to in H crease the sound energy received upon'Qa small surface placed at or near the-smallthe .interior; that is, the horn 4 is not as end of a horn; Inboth; such, the ho i'n is apt to cause a considerable loss, of sound energy by undesirable reflections. is

of the horn near the mouthithereof eitheri crosses the horn and being a second time from the opposite 'wall,;,then*'escaps through the mouthrDifiracti' l tardin actions of various sorts'also'cause loss 0 .sound energy in home heretofore It isan object of the resent invention to produce a horn that s all' avoid or diminish theselosses.

It is a further object of this invention to provide a horn-,that-will concentrate a proaching sound without reflectin bac into the atmosphere! any considerab e portion of the-sound received.

It is a further object of this invention to combine with an outer larger how one or more smaller inner horns in such a manner as to give the combination a higher efiiciency as a sound condensing instrument than can be obtained with any single horn of like aperture.

Other and further important objects of this invention will be apparent from the disclosures in the accompanying drawings and the following specification.

The invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

nand On the drawings:

Fi re 1 is a longitudinal section showing one orm of my invention.

Figures 2 to 5 are similar sections show ing modified forms.

As shown on the drawings:

The external horn 1 in Figure 1 is of the conventional flower shape, that is to say. instead of being strictly conical, the sides flare more and more. as the bell end 2 of the horn is approached, while at the small end 3, the horn either becomes strictly conical or terminates in a cylindrical tube.

In. carrying out my invention, I place the horn 1 and coaxial with it an "other horn 4 which is of somewhat the same general shape. The bell end 5 of this horn IS-j lI-lfi fi the bell end 2 of the horn 1, not only'in the senseof being surrounded by it but also in the sense of being farther toward longas the born 1 and a portion of the dif A ference in length is between the bell'end 5 best illustrated in the: ca se ofan mcomi'n and-thebellend 2. The remainder of the sound. The soundrefiected from one-side difference in'length is between the small end 3:.of.the'fliorn1 and the small end 6 of the I hornl4. "The small end 6 is therefore in'both senses within the small and. of the horn 1.

The, several horns may be supported in any desired manner. Preferably, thesupports should be of a'sort that interfere as little as possible with the passage of sound through the horns. One form of support is by the use of radial strips of sheet metal p a fwiththe plane of" the strips parallel .to the common axis ofthe horns.

.Althoughthe born 1 and the horn 4 are both described as of the same general shape, the relation between the'curve of the wall of one horn and that'of'theother is not arbitrary... The shape of the horn 1 havin been decided, the horn 4 will be so she e that sound reflected from the protru mg part of the bell end of the horn 1 and arrivgng at the external surface of the bell end 5 of the horn 4 will be reflected in a direction that slopes toward the small end of the born 1 as it approaches said horn. When the sound is again reflected, from a point on the horn 1 nearer the small end, and so again arrives at the exterior surface of the horn 4, it is again reflected at such an angle that it will make further progress toward the small and 3 of the horn 1. In order to insure this rela tion between the several reflections of the sound, the wall of the horn 1 and the wall of the born 4 are not parallel but they approach each other as they approach the small endof the horn 1, and the curve of each wall is desi ed to accomplish this. In this way, not on y is reflection outward prevented, but the sound is confined within a continually narrowing space so that the intensity of the sound vibration is necessarily increased.

Sound arriving from outside the horn against the inner face of the bell 5 is similarly reflected by a third horn 7 within the born 4. of one another may be added. The bell end of each horn is inside of the bell end of the next lar er horn; that is, it is to the left of said em? as illustrated in Figure 1. The small end of each horn is inside the small end of the next larger horn; that is, it is to-the right of said end, as illustrated in Figure 1.

In the form illustrated in Figure 2, I have shown a conicalhorn 10 with interior nested horns 11 and 12. In Fi re 3, I have shown an; approximately para, 'olic, horn 13' with similar nested horns 14: within it. In ure 4, I have shownrahorn 15 of double curvature, the convex outwar Similar horns have shown a hornl'? with nested orns18 which are also of double curyature but: con vex in the direction opposite'tothatillus trated in Figure 4. Theseillustrations serve to show that the lDVGDtlOIli'iS applicable to horns of many shapes. The shape of. the external horn is not entirely arbitrary butpis determined bythe use tojwhichj the horn'is to be put, by its length, aperture, aiid jsmall end diameter, by the source, by the extent it is desired tornake use of the horn as a resonator, and by .the

pitch'and quality of the sound ;t o be amplifled or condensed. The inner horns ineach case have somewhat as the; outer one but are not a smaller scale." They are designs "from the shape of the .outer hornfas explained in describing Fi ure 1. c

When the Iiorn is used to amplify the sound from a sound-emitting instrument instead of to concentrate sound..for a sound- If desired, still further horns inside Figart nearest' the bell being 1 1 r nested within th horn15.' In Fi' re 5,"I"

distance to the sound. 1

the same general form mere co res on receiving instrument, the several horns may be, but need not be, arranged along a common axis, and the large ends of the several horns preferably are, but need not be, in one plane. Their size and shape is determined chiefly by the Sounds which they are to reinforce, and with which they must therefore resonate.

In the operation of the device, sound from outside the instrument arrives at the bell end and is received upon the inner surfaces of the several horns. These reflect the sound to the outer surfaces of the horns next within, which reflect the sound again to the inner surfaces of the surrounding horns, but nearer the small end thereof. This process is re peated until the sound emerges at the small end of the-horn and arrives at the ear or other sound-receiving instrument. No reflections toward the bellend'of the horn occur andso no sound is lost by being re- Elected back into the atmos here.

When the horn is use to amplify the sound from-a sound-emitting instrument, insteadoi to concentrate sound forasoundreceiving instrument; the reflectionswill alwa s" be toward the bell end of the horn, an so no ener is lost by any sound being reflected back into the sound producing instrument.- e

@T amawarethat numerous details of constr'uetion may be varied through awide ran "'e without departing purpose-limiting the patent granted, otherwise than necessitated by the prior art.

I claimas my invention:

In a sound-conveying device, oi&iested:spacedhorns of mishin'g length, the shorter bein ref nishing shortof the corresponding end of the next outer horn, the surfaces of said horns apprqachingone another toward the small ends thereof, whereby'bp used portions of the surfaces of adjacent orns"'are'- non-parallel.

In testimonywhereof I havehereunto subscribed my name in the presence of two subsei'ibing'witnesses;

ARTHUR'LLFOLEY- a plurality inside 'and Witnesses:

J OHN 'P. CA PBELL, VrRon, T. FnANKLIN.

f'romthe principles i of; his invent1on,- 'and"I- therefore do not successively di as toFbOth'ends 0' each horn 

